Focusing finder for lanterns



, Y A1,461,418 y c. o. HARRINGTON- FocUsING FINDER -FoR LANTERNS Filed 'June 2, 1921 sheets-sheet 1 July- 1 0, 1923 41,461,418`

v c. o. HARRINGTQN FocUsING FINDER FOR. LANTERNS Filed June a, 1921' 'zfshepts-Snet 2 i mi 'Parasite .tary ic, reas.

naar

cLIuToN o. HARRINGTON,

or cHIcaeO,

F ILLINOIS.

' rocusme FINDER ron Lau'rnmvs."

Application filed June 2, 1921.

To all whom t may concern: y

Be it known that I, CLINTON O. HARRING- TON, a citizen of the United States, and a resident of Chicago, in the county of Cook and Sta-te of 1llinois,have invented certain new and useful improvements in Focusing Finders for Lanterns, of which the followin()r is a specification.

y present invention relates to means for i@ focusing the source of lightv in lanterns adapted .toproject rays in a given direction, for instance in such lanterns as 'may be employed for railway signals, locomotive and other headlights, motion picture machines, l5 etc..

' Lanterns of the kind to which the present improvements are chiefly applicable include a lens or -a reflector for directing-the rays of light. The source. of light-isfrequently an the incandizable filament is concentrated, that is, confined to comparatively small distances from a middle point.. As is well understood, the most efficient projection is had when the maximum number of rays emanate from a small `area or space atthe focus of the lens or reflector, and therefore the aim in such cases usually is to. have theconcentrated lamp filament as close to such focus as conveniently may be. In railway signal practice it is often desir.-

able to have the filament slightly away from the true focal point, but in any event the object always is to adjust 'the filament `to that position in which it gives the best results.` j y I Comparatively few of the concentrated filament lamps found in service'havetheir respective filaments in such exact relation to the base or plug elementof the lamp as 40 to make the lamps interchangeable Vwherever they may be desired to be used and provide the desired result. lt isvtherefore practically necessary to adjust each lamp individually in the The usual practice in railway signal work, when applying a new lamp to a lantern, is for one man to mount the mast or other nipulate the lamp adjustably while another man takes a position say a thousand feet down the track and observes the results of the various adjustments being made, this ment of the lampmay tration and description of theadjustment delantern in which it is to be used.

structure supporting .the lantern and maserial no- 474,543.

work being done in the night time, the man downthe track signaling with a lantern as tothe results, and thus'in the course of say from one to three hours the lamp is focused su-iliciently well for service.

In focusing the lamp provision must bel made for moving it vertically, from side to side, andalso in fore-and-aft directions. 1n the common practice to which I have just referred provision is made for adjusting the lamp in these three ways. ln my copending f application filed March 22, 1921 as Serial No. @444 on `a method of maintaining `a source of light in a desired position in a lantern, l haveillustrated and describedA the lamp adjustment device illustrated herein in Figs. l and 2, according'to'which the filaj be moved vertically, horizontally, and in fore-and-aft directions, and in each instance without amodification of any other adjustment made. By reference to that application a. more full illusbe had. In my said copending application have also I illustrated and described a finder device of the same general character as the one herein disclosed and similarly applicable as an attachment to thelamp adjustment device. `According to that finder device one shaft of light falls directly upon a ,translucent chart through a small aperture, the beams passingthro-ugh a cham-v ber which excludessubstantially all light but those constituting the relatively small shaft. That device also includes a second chamber through. which is cast by reflection a relatively long and narrow shaft of light which falls upon a second translucentjchart, \the second light shaft emanating Afrom the source /at av materially large angle with' reispect .to the beams 'constituting the direct shaft. According to that-device theoperator can make upon the one chart a reading of the relative position of the source of light in vertical "and lateral directions, and upon the second chart a reading of its relative position in fore-and-aft directions, and hav-l ing made/a rec-0rd of the desired relative position of the source in that particular vinstallation .he can'repjlace lthe burned out lamp Y in a very brief space of time by simply. inserting the new bulb and adjusting the source vice may j iti/iii m Laetrile in the several directions until the light shafts 2O and the 'frame cross member 2l respec-.f are lndicated on the two charts in accordtively. The vertically adjustable frame 22 ance with ythe record previously made. is carried slidingly by the 'vertical rods One object of the present invention is to mentioned and is raised and lowered-by the slmphfy construction withoutloss of'advanfinger wheel 23. The frame 22 carries twoV 70 tage, reducing the size and weight` of the fore-and-at parallel rods 24 and the framefinder and ldispensing with one chart, thus 25`is. mounted slidi'nglv thereon. The framev enabling the operator to make his original 25 carries two laterally extending rods 2b record and his subsequent adjustments in and the frame 27 -is mounted slidingly on vlew of a single chart, and obtain lin a more these. The lamp 28 having the concen- 75 .,easyand simple way the important and chief .tratedfilament 3() is mounted rigidly on object and advantage offocusing or adjust'-l the frame27. 'By turning the screw 31the lng the lamp' with greater ease, celerity, and, frame '25 is moved in fore-and-aft direci for the most part with greater 'accuracy than tionscarryingthe frame 27 with it, and by 1,5' is possible according to the means'and methturning the screw 32 the frame 27 is moved 80 ods known prior -to my inventionsto which in lateral directions.

reference is made herein. Inasmuch as the claims herein aredirecb` -In the accompanying drawings, which ed to the -iind'er device alone it is deemed form a part ofthis specification, Figurel` sulicien'tgto` showin merely a general way 4 20 shows in'fragmentary'form a railway signal how the various adjustments of the lamp 85 lantern of approved construction, parts of are made, and' to point out the essential fact .the body Wall being broken away to show that the filament 3() is adjustable in these the improved finder in side view upon the three directions. For a full disclosure of lamp-adjustment device; Figl 2 is an enthe lamp-adjusting device reference 'may bc larged rear view with the chart of the tindyhad to my said @pending-application. 90 er partially broken away to show more clear- The finder device is shown as comprising l how the iinderas a. whole is applied to top, bottom and side walls 35, 36,r 37 and 38` the adjustment device shown ,in F ig. 1; Fig. respectively and.` an end wall 39. A mirror- 3 is a. top 'plan of the finder device partly 'supporting arm 40 extends laterallyv and broken away to show construction and arthen for\vardly,'and a pair of'legs 41 extend 95 rangement of otherwise concealed parts;- downwardly, the walls, arm and legs being F ig. 4 is a front end view of theiinder and in my practice cast from aluminum. The small fragments of the parts by which it is bottom wall .36 carries a boss 43 bored to supported; and Fig. 5 is .a-'sectional view accommodate with an accurate but sliding on the line 5-5 of Fig. 3. fit the studl 19, and the legs 41 are accu'- 100 The signal lantern 10 is of well-known rately surfaced at 44 `to press against the l construction. It has a lens 11 in Jfront andl studs 18. The finder as a whole may thus a. verticallysliding door `12 permitting enbe readily placed in operative position and trance from the rear. vIt is to be understood removed thereform. I 40 that the lantern is secured to a signal mast 'The chart 45 consists of a translucent 105 or other structure, and at a considerable plate marked with vertical lines lettered A elevation above the railroad track. Ordito l inclusive andhorizontal lines um-. having several bered 1 to 9 inclusive after the well known differently-colored glass screens or roundmanner employed in vmarkingunaps 'and 45 els operatively positionedin front of the other charts. The desired translucency may 1.10 lens whereby different signals maybe given be obtained by sand-blastinga clear plate through the movement of the spectacle deof .glass on one side orin other ways well vice, all ,as is well understood in the art. known and the chart may bev of other mate-. The mounting of the'lamp above the ground rials suchas Celluloid, The markings on Y and the use if desired of such a.spectacle the chart may be by etching or by the appliil@ are not illustrated but are mentioned to 4cation of paint or ink. The chart is held show the application of these improvements crosswise of the chamber. -preferablyat the to a railway signal lantern of that type, end thereof, as by screws 46 and a clamping The desideratum is that the lamp within the frame 47.

A fairly large hole 50 is bored' through 220, lossof tlme at replacement periods as possithe end wall 39 and covering this hole'is the ble, and With the lamp so positioned' as to plate 51 having screwfholes large enough tn project light most eii'iciently. Y provide considerable play with respect to e lamp-adjustment device includes an the screws 52 whereby the plate may be @0 L-shaped` carrying frame 15 secured" by moved adjustablv tor calibration and held wie screwsito the lantern bottom or base, and in the desired position by screws or prefer` carries twolateral vertical rodsl and a ably by solder in additionto the screws. middle vertical threaded rod 17. each side The plate51 is provided' with a relatively rod having a stud 18 and the middle rod small hole or opening 53 therethrough. and @il having a stud 19 projecting above the ear in this connection it is pointed'out that the lso plate `is positioned in the angleshown so` thatthe formof the orifice 53 when-viewed in the directions of the light shafts irespectively passing through the hole-and defined by it will be substantially the same.

" The arm 40icarries a reflecting mirror 55 held in place by the" ring-like plate 56 se-V cured by screws 57. Within the chamber defined. by the body walls there isa Second mirror 60 similarly -held in place l'ipon'a` carrier 61 mounted for rocking movement upon a vertical pin 62 rigidly secured in the top and-bottom walls of the casing.` The mirror carrying device .61` may therefore Y rock on the pin 62,:,and means for holding lar relation comprise the it in a given 'an screws 66- threa edd in the casing wall,- the advancing of one and the retracting ofthe other givingthe desired' mod'ication inthe angle ofthe mirror 60. The inirrorO is also preferably given a slight inclination from the vertical, which may be in one direction or the other and which is well shown in Fig. as being such as to throw;7J upward .thelightshat strikin the mirror from 'the direction'of 'the o't er mirror through hole 5 3.,

The 'arrangementof the .several-parts in vthis so referred yconstruction iswell illustrat in Fig.l 3, which is substantiallytrue to scale, as are the other figures The la ment 30 is shown inrFig.' 3 at whatwe will assume to be the focal point of the lens 11.

It is thus clear that light rays emanating from the filament 3() will reach vand pass through the vhole-v53 from two directions,

one'being direct and shown by the dotted line Y68- and' the other being indirect or by reection land shown by the lines 69 and 70,

bothshafts falling on the chart and be?.

y ing visible on the outer side thereof.

. Owing tothe dierence in distance from the filament 30 to the orifice 53 andfrom the orifice 53 to the chart 45 the direct light 45 i which is proportionately larger than' the shaftwill appear upon'the chart las a spot filament'itself, as substantially` indicated at 75, Fig. 2, which indication also shows that this direct shaft'falls `upon the chart at its middle point when the filament'30 is at the focal point of the lens, assuming that the instrument has been accurately positioned in the lantern.' It is unimportant in practice justwhere, within the reasonable limits of the chart, the light shaft indicated at .75, Fig. 2, may fall. 1

The spotor indication 76,' Fig. 2, is that for the reflected shaft from the mirrors. It is relatively smaller than the indie-'ation 75 because the distance along lines 69 vand 70 to the orifice 53 compared withlthe'distance from 53 to the mirror --60 and thence lto 4chart 45 along line 71 is greater than the ratio of distance 30 to -53.to distance 53 to 45. l

practice the exact 'desired location of the filamentv with respect tothe lens' llfis first determined in any approved way,vas by the experimental test manner inthe early part of this specification described. Thereupon. the fir-der device' is operatively positioned on tl; xstud's' l8, and 19 and reading made of' the position of the s ots of light as and 76 onl'the chart 45. ccording to the requirements of a particular 'installation, or dueto the factthat the lamp# holding-and-adjusting device may not have been positioned withpreciseaccuracy, due to -slightvariations in machine work, these lightspots 75 and 76 may not be even close to the theoreticalpositions shown inFig. 2'

when the filament is properly adjusted with respect to 'the-lens. vThis is immaterial.

Whateverthe position of the spots 7 5y and 76 respectively provesy to be the 'adjuster simply makes a record of them, either in a book which he may carry with him from time vto time or, preferably, upon a tag or" other card-which he may leave within the I lantern for future` reference. Let us assuine that after making the preliminary ad-l justxfnent4 of the filamentv to determineits proper relative position the light beams are found to register at 75 and76. -The record he would thereupon .make from a reading of the chart-might be Direct spot- E-5; Reected spot E2. `Since the s ot 75 shows4 the relative location of the fi ament' in both up-anddown and lateral `directions of adjustments it is onlynecessary to con- Sider thevariation in position of the spot 76 caused by movements of the filament in fore-.and-aft directions, and since theforeandaft movements of the filament cause the` spot 76 `tomove inlateral directions'on the chart, it isreally immaterial what the ver-- tical position of the sp'o't 76 maybe. The record for spot 76 would be full enough if' 'it merely recited E `The ltilt of the mirror 60 from the vertical determines how far above or below this middle point of the chart the spot 7 6 will be,and such separation of the two spots is made merely for con` venience in reading. the chart. A further convenience'maybe had/bymaking one of .the mirrors 55 or 60 of colored glass, as

ruby or green, in which case the spot 76 will appear in the color `of the colored re# flector. The mirror 60 might be vertical,` l

las

3l and 32, as v,fully described in my pending application) the. spots o 76 and 75 may, in an exceedii space of time, be brought to positions respectively, which establishes the filament exactly inthe position previously found to be correct.

ln this connection it is pointed out that the mirror 60 is adjustably mounted as by means of the screws 66 so that the spot '76 may be suitably positioned as midway of the chart, when the instrument. is calibrated prior to use. By means of this adjustment and-that provided for the plate the calibrator is able to overcome the effects of such differences in mechanical construction asalinost of necessity exists in the manufacture of instruments of this general class or kind.

in the laboratory, according to my practice, each instrument is carefully calibrated with respect to a filament accurately posi- `tioned .in standard relation to the studs lf3 and 19 which determine the relative position of the finder upon the lamp adj ustment device. Having thus calibrated each instrument sent out from the shop, and the studs 18 and i9 of the lamp adjustment de! vice being of uniform construction and arrangement in each ofthe lamp-adjustment devices installed, the lamp maint ainer, having provided himself with one of 'the tinders, may use it in turn upon all ot the installations of this kind whichv he may find on his section of the line, and, further. should one of the finders be lost or broken another may be substituted without prejudice to the use with it of any of' the records showing the desired adjustment in any installation.

While l have thus illustrated and described a highly advantageous construction and arrangement constituting an exceedingly simple, efficacious and readily-operable linder of the character described, l contemplate as being within vthe scope of the present invention various changes and modifications from what is herein specifically shown, as indicated by the appended claims,

ll claim:

l. ln a finder of the character described adapted to be positioned closely adjacent to a source of light to indicate relative positions of such source, the` combination of a relatively small. chart having markings associated therewith adapted to indicate relative locations of relatively small light spots thereon ,*and means for projecting upon the chart two lrelatively small shafts of light from a given relatively small source, with said shafts issuing from such source with a ma teriallylarge angle between'them, for delining two relatively small spots ot' light on the chart for indicating a relative position ofthe source of light.`

2, A ndcr of the character described com incinte pris'ing in combination a cha-rt, light-obstructing means .for maintaining the chart substantially tree of light beams from a given relatively small source except in predetermined relatively vsmall shafts, and means including a single passageway through said light-obstructing means for desite chamber walls, there beinga relatively i small light aperture at one end portion ot' the chamber, the arrangement being such that rays of light may pass through said' aperture as arelatively'small shaft and fall directly upon said chart, and means including light-ray divert-ing mea'ns tor throwing a second shaft of iight from said source through said aperture and upon said chart.

e. in a finder of the character described adapted to be positioned adjacent to a source of light to indicate relative positions of Such source, the combination of a 'translucent chart, and means including light-reflecting means tor projecting upon the chart two shafts ot light from a given relatively small source with said shafts issuing tronisuch source with a materially large angle between them for indicating a relative position of the source of light.-

5.l A finder of the character described comprising in combination a translucent chart, light-obstructing means for maintaining the chart substantially :tree of light beams from a given relatively Small source except in predetermined relatively small shafts, andv means including light-raydiverting means and a single passageway through said .lightobstructing means for delimng such relatively small shafts of light which fall upon i the chart, the rays which constitute one shaft passing through said passageway at materially large angle with respect to the rays which constitute the other shaft and pass therethrough. I

6. ln a finder of the character described vadapted to be positioned adjacent to a source liti till@ angle with respect to :a second shaft of light the -'bean-1s of which issue from the source at --a/ materially large the beams constituting said other shaft. y

, 7:'A finderv of the character described adaptedz to be positioned closely adjacent to a relatively small sourceY of'light and .comprising walls forming a chamber, means at one end portion'of the ,chamber'ior directing. a relatively,narrow shaft of light from such Lrel': 1.tivelysmall'source of light'through the chamber to show substantially as "-a small spot on a chartdevice,fand a chart device at the opposite end o/f said chamber. and conhaving a. normally stituting an attached art bf thefinder, and edv relation tto "said chamber walls and to said means forv directin a shaft of light, said .chart device, having a eldbrranged to receive said shaft of light,

fthe field of said chart device having' mark- Vings'j'deiining a'substantially large number of relatively small areas throughout the eld,

there being :indicating characters associated.

. .with said markings whereby a record may be made .in terms of saidcharacters to indicate various relative positions of the source of' light,.

8. A nder adaptedtolbepbsitioned ad'- `jacent to an adjustable source of light for ,determining` the relative position of the source vof having mar Milli; comprising a chart device`` gs thereon for indicating movement of the source of light in horizon! tal, vertical and fore-and-aft directions, and

zmeans for projectingl on the chart device -a plurality of limited areas of light caused by beams issuing from the source in various directlons.'

9. The combination of a hollow lantern body having a doorway in one part. thereof -and a lens` in another part thereof, a -man support for a sourcel of light within said body, and means carried by the A main support within the lantern body 7a'nd accessible through said doorway -for holding in readily removable relation thereto an optical finder applicable through said doorway for deter- A directions relative tothe lantern body, means including a translucent chart closelyadjm,

cena to the lantern body and having a field divided-into a substantially largenumber of relatively small, areas, adapted to receive rays from said source, and means ford'irecting upon the .charta shaft of lightl from said source' as a substantially-welldened spot for 'indicating -a relative position Aof adjustment of the source of light. y

CLINTON o. HARRINGTN. 

